1. Field of the Invention
The present invention relates to a scan driver for an organic light emitting display device (OLED) and, more particularly, to a scan driver that includes transistors of the same conductivity type.
2. Description of the Related Art
A scan driver supplies a scan signal to an active matrix (AM) organic light emitting display device (OLED). As the scan signal is supplied, a pixel of the OLED is selected, and a data signal is applied to the selected pixel. The pixel to which the data signal is applied stores the data signal and performs an emission operation in response to the stored data signal.
The scan driver is formed on a crystalline silicon substrate through a semiconductor fabricating process. The scan driver formed on the crystalline silicon substrate is electrically coupled to the pixels.
In recent years, a System On Panel (SOP) technique of forming the scan driver on an organic substrate on which an OLED is also formed has been utilized. Conductivity type of transistors of the scan driver may be the same as the conductivity type of transistors of the pixel so that the scan driver can be formed on the same substrate as the OLED. However, a complicated circuit for the scan driver having transistors of the same conductivity type as the transistors of the pixel does not yield satisfactory characteristics and requires a complicated fabricating process.
Therefore, there is a need for a simple circuit for the scan driver having transistors of the same conductivity type as the transistors of the pixel.